this is the most I've ever spent on a backpack. I was in need of a big camping backpack, and came to this Osprey listing. Though pricey, it is really worth every penny. it has tons of pockets and storage departments, and has good waistline support and shoulder straps are cushy and comfortable. I am able to lug around 40-50 pounds of load no problem, and best of yet the bag has insulation so your back doesn't get completely soaked in sweat! (it is dramatically better compared to normal backpacks, but yea, it still gets warm).
I love this Osprey and will buy another in the future, shall my wife decides she needs one as well! This size is perfect... I'm 5'7 160 pounds and it fits well. You can go up one more size for my frame I believe. but the smaller one will be too small/less useful in my opinion for folks in my height/frame range.
enjoy.